Google is starting to unravel the secrets of its new Fuchsia operating system, sparking lively discussions in software developer communities. After presenting a working prototype of the potential Android successor earlier this year, a first manual for developers has now appeared. Although the document referred to as “The Book” was previously accessible via Google’s Fuchsia code repository, changing the name of the file has now brought it into the public eye. The first thing that Google clarifies in the documentation is: Fuchsia is not Linux. The OS consists of a kernel called Zircon, which is based on the Google developed microkernel infrastructure lk (for “Little Kernel”). This includes a corresponding userland, graphic interfaces (Magma, Escher and Scenic), the UI toolkit Flutter and the programming language Dart. Both on Hacker News and Slashdot, the new operating system is already hotly debated. In the developer communities, it is above all disputed whether microkernels are a good idea for the areas of application intended by Google. Away from the GPL, away from Java. Unlike Android, which includes a significant amount of GPL-licensed source code with the Linux kernel, all Fuchsia components are available under more licensable licenses. Fuchsia is a combination of BSD, MIT and Apache licenses. For some parts of the open source community, this is criticized, because developers do not necessarily have to share their changes with the community in the new OS, as is the case with the Linux kernel. Another motive for Google’s decision for a completely new mobile and IoT operating system could be the lawsuit Oracle is conducting against the Android maker. There are billions of dollars in this space that Google may have to pay to use Java in Android. Whatever Google’s reasons for developing Fuchsia are, the company makes no secret of the fact that sooner or later they want to replace Android with the new OS. Last but not least, to solve Androids security problems from the ground up with a new infrastructure concept. Interested developers should look at the new manual at least once.